A little-known, sometimes symptomless sexually transmitted disease is set to be the next superbug within a decade — if people don’t wise up about their sex lives, experts are warning.

Mycoplasma genitalium, or MG, is a sexually transmitted bacteria that can cause pelvic inflammatory disease and, ultimately, infertility in women if not treated properly.

Symptoms of MG can be similar to gonorrhea and chlamydia — but often, there are no signs of an infection at all. That means some people may not even be aware they’ve been infected until bigger problems arise.

If left untreated, MG, which was first discovered in the early 1980s and spreads through unprotected sex, can also develop a resistance to antibiotics.

“This is not curing the infection and is causing antimicrobial resistance in MG patients,” Dr. Paddy Horner told the Telegraph. “If practices do not change and the tests are not used, MG has the potential to become a superbug within a decade, resistant to standard antibiotics.”

In women, MG can cause a burning sensation when urinating and pain or bleeding during and after sex. Men might experience watery discharge from their penis.

In the UK, health experts launched new guidelines for the treatment and diagnosis of MG, saying around 1 to 2 percent of men and women have contracted the STD, according to the Telegraph. Some clinics, however, have put that number as high as 38 percent.

The new guidelines recommend a specific test for MG and that it be treated with a seven-day dose of antibiotic doxycycline, followed by a course of azithromycin.

“These new guidelines have been developed because we can’t afford to continue with the approach we have followed for the past 15 years as this will undoubtedly lead to a public health emergency with the emergence of MG as a superbug,” said Horner, who helped author the new guidelines.

Dr. Olwen Williams, president of the British Association for Sexual Health and HIV, warned of much greater consequences.

“Potentially up to 3,000 women a year over the next 10 years could become infertile because of MG leading to pelvic inflammatory disease,” she said.